Memory usage

i have 16 gb of Ram installed and my system says only 12 gb is usable? i am running windows 7 home premium 64 bit. which says the max recognized is 16 gb. and the motherboard i have is a msi 990fxa-gd80 which can read up to 32 gb of Ram. is there any way i can get the other 4 gb usable? its a 4x4gb configuration so i don't think 1 of my sticks is even being used. if any one can help me with this... that would be great,


Extraordinary Member
Hmm. I've seen where 4gb of RAM on a 64bit system will say only 3.25gb is available. The usual way to sort this is to set Memory Mapping in your bios to enabled.

Quite possibly one of your RAM modules isn't seated properly?

Just a couple of thoughts....


Senior Member
go to start
type msconfig
go to boot tab
advanced options
make sure maximum memory is 0 and the tick box above it is UNTICKED
click ok
and ok again
then reboot


Excellent Member
Microsoft Community Contributor
There is always a chance some of your memory is bad, or as Elmer suggests, not seated and recognized.

If you open Resource Monitor (Task Manager-Performance) and look at the Memory tab, what does the graph along the bottom say as far as what is allocated to what.

i hope it isn't bad memory. I just got new RAM after two of two sticks tested bad. i RMA'd the two bad sticks and Crucial send me two new sticks of RAM. i tried reseating them and unchecking the boot tab. i haven't tried mapping them yet i'll let yall know how that goes


Excellent Member
Microsoft Community Contributor
I suppose there is a chance you could have a bad slot on the motherboard.


I just finished replacing 6 bad caps on my own motherboard. When I put the CPU, Ram and all the other stuff back on the board, it refused to boot up. I remembered that had happened to me before, due to two new sticks of Ram that I had installed.

So I took the newest sticks out and the board booted up normally. I cleaned the ram that I had taken out, with Denatured Alcohol and polished up the edge connector real nice. When I put those two ram sticks back in the board, I wiggled them from side to side just a tiny bit to really seat them firmly in their slots. After doing that, my PC now boots up normally and all ram is accounted for.

I've not actually replaced any so called 'bad' ram in many years. It usually fails because it's just dirty. I wash it and put it back and it runs just fine with NO errors.

If I had all the 'bad' ram that people throw away each year, I'd be a millionaire over night.

Just a little Tech-Tip from an old PC tech.

Cheers Mates!

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